Pump



Jan. 24, 1967 ovl ET AL 3,299,816

v PUMP 0r iginal Filed Nov. 9, 1962 2 Sheets-Sheet 1 FIG. 2-

INVENTORS MILAN 'MOMCHILOVICH 8 WALLACE F. RHODES BY/Z ATTORNEY Jan. 24, 1967 o c ov c ET AL 3,299,816

PUMP

Original Filed Nov. 9, 1962 2 Sheets-Shem 2 INVENTORS MILAN MOMCHILO 8 BY WALLACE F RHO ATTORNEY United States Patent UMP 4 Claims. (Cl. 103-6) This application is a division of application Serial No. 236,481, filed November 9, 1962 now abandoned.

This invention relates to a new pump designed more particularly :for supplying both air and oil to one or more oil burners.

In the system, air is supplied from a pump to a manifold connected to a plurality of burners, utilized from time to time, and oil is supplied to each burner preferably from the pump through a float control valve which maintains a supply of oil at a level just below that of the burners. In this system all of the burners are located at about one inch above the oil level, and as the oil is aspirated at the burner nozzle additional oil is drawn up into the bumer. Because the oil is lifted into the burner, it is impossible for the oil to flood the burner. The air in the manifold is maintained at a low pressure in the range of l to 10, and preferably about 3 to 5, pounds per square inch. Unused air is advantageously returned from the manifold to the pump, either to the air intake or the chamber in which the air rotor operates.

The pump is provided with two chambers located ideby-side on a common axis, with an impeller in each chamber. The larger chamber has an air intake and outlet, and the intake of the smaller chamber is connected with an oil supply and this pump delivers the oil through a suitable outlet. The air aspirates the oil in one or more burners which generate heat in one or more appliances such as a furnace, an incinerator, a clothes drier, a hot-water heater, etc.

Although various means may be utilized for supplying low-pressure air to the burner, the preferred equipment utilizes a rotary pump in which roller pistons are employed. These pistons are thrown toward the circumferential wall of the chamber of the pump as the rotor is rotated. The motor which drives the pump may be an electric motor. A 0.1 H.P. motor operating at 1000 rpm. is satisfactory for low heat requirements. For larger burners, a larger motor may be required. The motor is preferably constructed as a unit with the pump housing.

Both of the chambers in the pump, viz. the oil chamber and the air char-mber, are located in a single housing. The smaller chamber which is the oil chamber may be offset outwardly from the air chamber, or it may occupy space partitioned off from within the air chamber, or it may be located partially within the air chamber with the remainder extending out from the air chamber. The impeller within the oil and/ or air chamber may rotate, or

it may be a stator with the chamber rotating about it.

No wall separates the two chambers and oil escapes from the oil chamber in a small amount sutficient to lubricate moving parts within the pump.

The parts of the pump may be machined or stamped from metal or they may be cast of plastic such as an oilextended rubber or other thermoset plastic. Roller pistons are advantageously used in the air chamber and at least one spring-pressed fiat vane in the oil chamber. These impellers may be made of nylon or Teflon or the like which are light in weight and need no lubrication,

although they may be metal. They may be plastic coated, or they may be a metal shell filled with plastic.

It is desirable to circulate oil through the oil stator to maintain the pump at relatively constant temperature. It is possible to similarly circulate air through the air rotor. This prevents the pump from heating up with resultant rise in the temperature of the oil and air which would vary its performance even to the point of preventing the oil from being raised to any great height by vacuum.

The invention is explained in connection with the accompanying drawings, in which: 7

FIGURE 1 is a view in perspective of one end of a preferred pump, referred to herein as the back;

FIGURE 2 is a broken section on the line 2-2 of FIGURE 1, showing the oil inlet and outlet;

FIGURE 3 is a "broken section through the pump on the line 3-3 of FIGURE 1;

FIGURE 4 is a view of the pump on the line 44 of FIGURE 3, the front plate being removed, with part of the rotor shown in section and part broken away;

FIGURE 5 is a sectional detail on the line 55 of FIGURE 3, showing one of the roller pistons floating in the pocket in which it reciprocates; and

FIGURE 6 is a section on the line 6-6 of FIGURE 3 showing details of the oil pump construction including a passage between the vane chamber and the oil-outlet chamber of the oil pump.

The preferred oil-air pump shown in FIGURES 1 to 6 includes a generally cylindrical housing 56 closed by a front end plate 53 and back end plate 81. Within the housing is a rotary air compressor and an oil pump designed to lift the oil from the storage tank through the pump and supply it to the burner or burners. The air compressor is composed of an air rotor 43 within an eccentric air-compression chamber 68 (FIGURE 5) of which the housing forms the outer wall 66. The oil pump includes a non-rotating stator fastened to the back plate 81 by screws 92 and an eccentric oil chamber 82 (FIGURE 6) formed by a pump-cavity bushing recessed in that surface of the air rotor 43 which faces the back plate.

The bushing 90 is driven by the air rotor 43 by means of fixed driving pin 83 located partly in the rotor and partly in the bushing. The bushing is pressed to the back plate by an annular pressure sealing spring (usually about a 5-pound spring) 101 located between the bushing and the air rotor. This spring presses the bushing away from the rotor and seals it to the back plate. The O-ring 91 in a groove in the outer diameter of the bushing forms a seal between the bushing and the air rotor, preventing oil from leaking between the bushing and the rotor and thence over the face of the end plate 81 into the air chamber 68. Thus the bushing not only forms an eccentric oil pump cavity but also serves as a stationary seal at the O-ring 91 and also a rotating seal at the interface between the bushing and end plate 81, and because of spring 101, both seals are self adjusting. Both sea-ls are preferably designed to withstand as much as a 10-foot oil head. Capillary action lubricatesthe interface bet-ween the bushing 90 and the back plate 81 and also the surface of the main bearing 84 contacted by the air rotor 43. No lubrication is necessary for the air compressor, because no surface of the air rotor 43 is in sealing contact with any adjacent surface of the compressor and friction is lessened between the air rotor and the roller pistons because of the air cushion between them, as will be explained in what follows.

The drive shaft 45 which passes through the outer pump bearing 51 drives the air rotor 43 by means of coupling 49 at the front of the air rotor. There are two pins 48 on the front of the air rotor 43 which extend into coupling 49, and two similar pins (not shown) evenly spaced therefrom, on bushing 46 which extend into the coupling 49. These cause the rotor to turn with the drive shaft 45. This coupling is of Teflon or like material so that the operation is quieter than if there were metal-t-o-metal contact. The outer pump bearing 51 is positioned inwardly by means of three adjustment screws 107 in the front end plate 53 so that the bearing 51 registers on air rotor 43 and maintains a clearance between the end plate 53 and the surface of the rotor adjacent to it. The bushing 46 acts as a coupling between drive shaft 45 and air rotor drive pins 48. O-ring 50 acts as a stationary air seal. The drive shaft is rotated by any suitable power means, but preferably by an electric motor which may be a shaded pole motor or a split phase motor, the former being preferable from an economic standpoint.

The main bearing 84 is press-fitted into the oil pump stator 80 and extends into the recess 94 in the back plate 81. The other end of the bearing terminates within the air rotor, and near its front to give adequate support for the rotor. The air rotor 43 rotates about this hearing, carrying the bushing 90 with it. Thus, there is no drive shaft for the oil pump. The oil-pump cavity is bounded on the front by the air rotor and at the back by the back plate. The cavity 68 of the air pump is bounded on the front and back by the front and back plates 53 and 81.

Two roller pistons 67 within oppositely disposed roller cavities 71 (FIGURE in the air rotor are cushioned against the wall 66 of the air cavity.

A cylindrical air-cushion duct 70 (FIGURE 5) in the forward wall of each roller piston cavity 71 connects the air chamber 68 with the cavity, so that the air under each roller piston within the cavity is pressurized and the lift created assists centrifugal force in propelling the roller pistons toward the chamber wall 66. The pressure lift created by the passage of compressed air through duct 70 eliminates much of the vibration and heat which would otherwise be created by the roller pistons. The roller pistons are adapted to move in and out of their respective cavities with minimum touching of the cavity walls, and this movement depends upon the differential in the air pressure in front and in backof the rollers. The operation of the air rotor is relatively noiseless because (1) on starting the pump, the contact between the roller pistons 67 and the wall 66 of the air chamber is rolling contact, and (2) as the compressor operation continues and air under pressure is forced into the roller piston cavities 71 through ducts 70 behind the roller pistons, the pressure floats said pistons in air, so that as they are reciprocated in and out of their repective cavities they make little, if any, contact with the cavity walls.

The capacity of the air compressor is made adjustable so that the same pump can be used for installations requiring more or less air, depending upon the number of appliances or the like which are to be supplied with air. The air enters the compressor through the silencer 40, passes through the conduit 102 into the air chamber 68, and then passes out through the conduit 105 to the manifold through the'connection 41. The small conduit 62 connects with one end of the return passage 60 (FIG- URE 4) out into the wall of the housing 56, or, if preferred, in the face ofgthe back plate, and the other end connects with the air intake 102 through the small conduit 61. The amount of air recirculated through this return is controlled by the adjustment screw 63. Proper adjustment of this screw by factory or field adjustment keeps the compressor from operating at maximum capacity unless necessary.

The flat pumping vane 95 of the oil pump moves in and out of the oil stator 80, being pressed out by the purposely weak drive spring 96 (FIGURE 6). Further pressure needed to seal the outer edge of the vane 95 against the inner surface of the wall 93 of bushing 90 is provided by oil returned from the oil chamber through a small opening 103 between the oil outlet 99 in the stator and the inner end of the vane cavity 104 (FIG- URE 5) in the stator. As the air rotor rotates it rotates the bushing in the oil chamber and this causes reciprocation of the vane in the vane cavity, creating suction which lifts oil from storage to the pump .through oil inlet 98 and forcing it out through outlet 99. In this pump the stator is stationary so that one edge of the vane slides against the stationary end plate, minimizing frictional wear.

Thus, as the bushing is rotated about the stator, oil is lifted into the pump through inlet 98 and expelled through outlet 99 by movement of the vane 95 adjacent the inner wall 93 of the bushing. Simultaneously, air is drawn through the mufiler 40 into the air chamber 68 through conduit 102 and expelled under a pressure of several pounds through the outlet 105 which connects with a manifold if a manifold is used. Operating at only 1000 revolutions per minute, a lift equivalent to 30 inches of mercury is possible.

As best shown in FIGURE 2, the oil in entering the oil pump and also in leaving the oil pump, travels through the stator. Heat generated in the air compressor is transmitted through the heat-conducting parts of the air rotor and oil bushing :to oil in the oil cavity, and thence to the stator, so that the circulating oil continuously cools the air rotor and prevents it from heating to an undesirable temperature.

The main bearing 84 is not connected to the drive shaft. Consequently, a very low torque is required to put the pump in operation. 7

To equalize the thrust developed by forcing the air and oil into their respective outlets, these outlets are advantageously located opposite one another, as in FIG- URE l, where the air outlet 105 (to which the manifold connection 83 may be attached) is opposite the oil outlet 99.

In a pump of the type shown in FIGURES 1 to 6, with an inside volume measuring about 4 inches in diameter and 1.5 inches deep, with the rotor opearting at 1000 r.p.m., it is possible to pump thirty gallons (or liters) of oil per hour with sufficient air to aspirate this in a plurality of burners. The pressure of the oil at the outlet of the pump is relatively low, but when the oil exit from the pump is closed the pressure may build up to 60 to 70 pounds, but soon returns to working pressure when the exit is opened.

Modifications in the structures shown are possible within the scope of the invention. For instance, the oil and air pumps and the burners used in the system described may be quite different from those specifically described.

The invention is covered in the claims which follow.

What we claim is:

1. A pump which comprises two rotary pump units within a housing, one for air and the other for oil, each of said units comprising two elements, namely (1) an impeller with vane means adapted to be reciprocated with respect to the same, and (2) afluid chamber in which the impeller is located, the fluid chamber of the air unit being defined solely by the impeller within it and the housing, the fluid chamber of the oil unit being defined solely by said housing and both impellers, the impellers being side-by-side with oil from the oil unit lubricating the air unit, a drive shaft, the two elements of each unit being relatively rotatable by virtue of the fact that the drive shaft is operatively connected with one element of each unit, and fluid inlet and outlet means for each fluid chamber.

2. A pump which includes a generally cylindrical housing closed at both ends, two rotary pump units within the housing, one for air and the other for oil, each of said units comprising two elements, namely (1) an impeller with reciprocal vane means associated therewith and (2) a fluid chamber surrounding each impeller, the chamber of the air unit being defined solely by (a) the impeller Within it, (b) the cylindrical portion of the housing, and (0) both end closures of the housing, and the chamber of the oil unit being defined solely by the two impellers and the closure at one end of the housing whereby oil from the oil unit lubricates the air unit, a drive shaft passing through the closure at t-he other end of the housing with which shaft one element of each unit is operatively connected, the two impellers being arranged sideby-side with respect to the longitudinal dimension of the drive shaft, and separate fluid inlet and outlet means for each chamber.

3. A rotary pump which includes an impeller with reciprocable vane means associated therewith, a generally cylindrical wall member which surrounds the impeller and forms the pump cavity, means for moving the impeller and wall member relatively to one another, a first closure at one end of the cavity attached to said wall member and a second closure at the other end of the cavity attached to the impeller, and a spring between said wall member and said first closure pressing said wall member against the second closure.

4. The pump of claim 1 in which the impeller of the oil unit is a stator with a passage therethrough for the passage of oil between (1) the fluid chamber of the oil unit and (2) a location outside of the oil unit.

References Cited by the Examiner UNITED STATES PATENTS Minor 103-136 Jackson 103-136 Smith 103-6 King 230-158 Kiekhaefer 103117 Dall 103-123 Whiteley 103136 McManus 230-158 Senninger 103-6 Bidwell 103-136 Witherell 103-6 Sanborn 103-6 Snyder 103-117 Vlachos 103-136 Katzenberger 230-149 Rineer 103-123 Clark 103-136 Meely 103117 Great Britain.

MARK NEWMAN, Primary Examiner.

DONLEY J. STOCKING, Examiner.

W. L. FREEH, Assistant Examiner. 

1. A PUMP WHICH COMPRISES TWO ROTARY PUMP UNITS WITHIN A HOUSING, ONE FOR AIR AND THE OTHER FOR OIL, EACH OF SAID UNITS COMPRISING TWO ELEMENTS, NAMELY (1) AN IMPELLER WITH VANE MEANS ADAPTED TO BE RECIPROCATED WITH RESPECT TO THE SAME, AND (2) A FLUID CHAMBER IN WHICH THE IMPELLER IS LOCATED, THE FLUID CHAMBER OF THE AIR UNIT BEING DEFINED SOLELY BY THE IMPELLER WITHIN IT AND THE HOUSING, THE FLUID CHAMBER OF THE OIL UNIT BEING DEFINED SOLELY BY SAID HOUSING AND BOTH IMPELLERS, THE IMPELLERS BEING SIDE-BY-SIDE WITH OIL FROM THE OIL UNIT LUBRICATING THE AIR UNIT, A DRIVE SHAFT, THE TWO ELEMENTS OF EACH UNIT BEING RELATIVELY ROTATABLE BY VIRTUE OF THE FACT THAT THE DRIVE SHAFT IS OPERATIVELY CONNECTED WITH ONE ELEMENT OF EACH UNIT, AND FLUID INLET AND OUTLET MEANS FOR EACH FLUID CHAMBER. 